I'm not so shure Rpcert4.dll is responsible for you not being able to open windows by clicking hyperlinks.
If there's a problem there, it's usually due to other dll's getting unregistered or corrupted.
Maybe start at the beginning:
To start with, do some cleaning:
Shut down Internet Explorer and Outlook Express.
Go to Control Panel/Internet, and clear your temporary Internet Files.
Click on Settings/show files, and delete all cookies there.
Now go to the Advanced tab, and click Restore Defaults.
And go to the Security tab, and click restore defaults there as well.
Now first try setting IE5 as your default browser. Go to IE tools/internet options/programs and turn on the check box for IE to check if it is the default browser. Shut down and restart IE. When it asks to be default browser, say yes.
Also have a look at this MS article:
Internet Shortcuts in Outlook Express Don't Start Browser
It appears to refer to OE, but it's relevant all the same.
Now go to Start - Run (type each line below separately, then press OK)
regsvr32 Shdocvw.dll
regsvr32 Oleaut32.dll
regsvr32 Actxprxy.dll
regsvr32 Mshtml.dll
regsvr32 Urlmon.dll
Note: you should see a brief message after each entry.
Reboot and test IE - New Window, repost with your results.
Finally, some (and this does refer to Windows 98 only) have reported that reverting back to an older oleaut32.dll version from their CD did the trick.
So my next advice is to restore Oleaut32.dll from your Windows CD-ROM with System File Checker:
How to Extract Original Compressed Windows Files
Good luck,